Friction twisting unit

ABSTRACT

Method and apparatus for false twisting one or more strands is disclosed. The apparatus includes an improved false twisting unit operable to impart false twist into one or more strands as the strand or strands are advanced and engaged by the friction twister. Guide means are provided for directing each strand in an inactive path remote from the twister while the twister is being threaded up, during the interval when the twister is being brought up to speed, and while advance of the strand from its supply to its take-up is commenced. Subsequent to these steps each strand is shifted into an active position where it engages with the friction twister to be twisted thereby.

United States Patent Richter [54] FRICTION TWISTING UNIT [7 21 Inventor: Hans H. Richter, Warwick, R.I.

1 [73] Assignee: Lessons Corporation, Warwick, RI.

[22] Filed: Sept. 10, 1970 [21] Appl. No.: 71,027

[52] US. Cl ..57/34 R, 57/77.4, 57/106, 57/156 [51] Int. Cl. ..D02g 1/00, DOlh 7/92, DOlh 13/04 [58] Field of Search.....57/34, 51.6, 77.3, 77.45, 106, 57/515, 77.4, 77.33

[5 6] References Cited UNITED STATES PATENTS 3,287,890 11/1966 McIntosh et a1. .;.57/77.4 3,527,043 9/1970 Sabaton ..57/77.4 3,029,591 4/1962 Scragg et a1. ..57/77.4 X

3,066,473 12/ 1962 Maeda ..57/77.4

Primary Examiner-Donald E. Watkins Attorney-Sha'tffert & Miller 57 ABSTRACT Method and apparatus for false twisting one or more strands is disclosed. The apparatus includes an improved false twisting unit operable to impart false twist into one or more strands as the strand or strands are advanced and engaged by the friction twister. Guide means are provided for directing each strand in an inactive path remote from the twister while the twister is being threaded up, during the interval when the twister. is being brought up to speed, and while advance of the strand from its supply to its take-up is commenced. Subsequent to these steps each strand is shifted into an active position where it engages with g the friction twister to be twisted thereby.

10 Claims, 3 Drawing Figures PATENTEDHBI I912 3.701. 245

INVENTOR HANS H. RICHTER ATTORNE S FRICTION TWISTING UNIT BACKGROUND OF THE INVENTION The present invention relates to improvements in friction twisters of the type disclosed, for example, in commonly assigned co-pending U.S. Pat. application, Ser. No. 48,167.

1. Field of the invention The present invention relates to method and apparatus for twisting strandular material. More particularly, the invention relates to an improved friction twister for imparting false twist to a textile strand or a plurality of strands and the method of employing the friction twister. As used herein, the term strand means any kind of strandular material capable of receiving twist.

2. Description of the Prior Art In commonly assigned co-pending US. Pat. application, Ser. No. 48,167 there is disclosed and claimed method and apparatus for imparting twist to textile strands. The apparatus disclosed therein includes a fric tion twister constituted as a hollow spindle having a first friction surface affixed at one end thereof and a second friction surface affixed in the opposite end of the spindle. One or more strands enter the hollow bore of the twister spindle and are drawn over the first friction means whereafter the course of the strand is reversed by means of a reversing guide, and the strand is sequentially drawn over the second friction surface at the opposite end of the twister spindle, Thereafter, each strand is directed upwardly once again through the hollow twister spindle and carried out the exit end thereof. With the strand thus threaded through the spindle the strand is advanced and the spindle is simultaneously rotated thus inserting false twist into each strand.

While the method and apparatus set forth in the prior cited application, Ser. No. 48,167 is admirably suited for imparting multiple turns of twist into the strand for each revolution of the spindle and for obtaining the further advantages as set out in the application, it has been discovered that the machine on which the false twister is mounted and the false twister itself can be threaded up more easily and expeditiously if the strand is situated in a position remote from active engagement with the friction twister during the threading-up procedure. Further, it has been found that the incidence of strand breaks in the regionof the false twister at the time when rotation of the false twister is first initiated and advance of the strand is commenced can be significantly reduced if not entirelyeliminated if the strand is held out of engagement with the friction twister until after rotation of the twister and advance of the strand is begun. Additionally, it has been observed that excessive abrading or cutting of the elastomeric rings which constitute the frictional surfaces at the opposite ends of the friction twister is substantially precluded if the strand or strands are not engaged with these rings until after the friction twister has commenced to rotate.

SUMMARY OF THE INVENTION Accordingly, the present invention comprises method and apparatus for imparting false twist to one or more running textile strands. In the instant invention each strand is directed through the hollow bore of a friction twister spindle and is maintained generally coaxial therewith by the provision of strand guides disposed at opposite ends of the twister spindle. As each strand passes in a first course through the bore, it is reversed at the exit end of the bore by means of a reversing guide, so that it loops back to the entry end of the bore to be drawn sequentially through'the bore of the twister spindle on a second pass. During the threading-up phase of the friction twister the strand is directed through the opposing yarn guides on both passes. Consequently, notwithstanding that the friction twister is provided-with friction surfaces in the form of elastomeric rings or similar friction members disposed at opposite ends of the spindle the strand is guided in an inactive path spaced from these friction surfaces. The guides have exit slots which permit the strand to be released manually from the strand guides to an active twisting position where the strand is engaged with the friction surfaces after the twister is rotated and linear advance of the yarn is commenced. Upon release of the strand from the guides, tension in the strand serves to draw each strand into engagement with the opposite frictional surfaces, the friction twister then serving to impart false twist to the advancing strand.

One object of the present invention is to provide a friction twister which is capable of false twisting a textile strand by means of frictional engagement of the strand with a plurality of separate friction surfaces within a single rotatable spindle and including means for retaining the strand in an inactive position, nonresponsive to the action of the friction twister, until the twister is brought up to speed and linear advance of the strand is commenced.

Another object of the present invention is to provide a friction twister for imparting twist into an advancing strand, the friction twister having a hollow bore with friction surfaces disposed at opposite ends thereof, the friction twister also including strand guiding members approximate to the opposite ends of the spindle and operable to guide the strand through the bore of the spindle in a path remote from the friction surfaces, the

guides being adapted to release the strand for engagement on the friction surfaces when desired.

Still another object of the present invention is to provide a friction twister which is easily threaded up.

Other objects of the invention in part will be obvious and will in part appear hereinafter.

DESCRIPTION OF THE DRAWING FIG. 1 is a transverse sectional view through a multistation processing apparatus embodying the friction false twister of the present invention;

FIG. 2 is an enlarged elevational view of the friction twister of the present invention in operative association with a portion of its mounting swing, the friction spindle and a portion of the mounting swing being shown in section; and

FIG. 3 is a top plan view of the friction twister of FIG. 2 with the strand being illustrated in solid lines when in its inactive position and in broken lines in its active position engaged with the false twisting means of the friction spindle.

DESCRIPTlON OF THE PREFERRED EMBODIMENT The friction twister of the present invention is suitable for use in any apparatus wherein one or more strands are drawn from a suitable supply source or supply sources and directed along a path for false twisting and ultimate take-up on a winding form. In FIG. 1 the invention is illustrated in conjunction with apparatus comprising a conventional false twist machine for texturing strandular material. characteristically, such false twist machines include a plurality of similar strand processing stations arranged in side-by-side relationship along a common frame. Although such machines include a plurality of individual stations it will suffice to describe but one of these stations, it being understood that the other stations are identical to the one being described. Thus, turning to FIG. 1, each station comprises a friction false twister 10 operable to rotate at a speed commensurate with the rate of travel of strand S therethrough. Twister 10 operates to twist the strand below the twister and to untwist the strand thereabove. The untwisted strand from the twister 10 is passed around on a tension controlling feed roll device 12 and from there advances to a processed strand takeup unit 14, positioned above the device 12.

A heating and twisting zone underlies twister 10 and includesan elongated strand heating unit 16 common to all of the stations along the machine, the heating unit being heated by suitable heating elements not shown. The heating unit 16 has a strand-receiving groove or slot 18 in alignment with each twister 10. As illustrated, the strand from supply package 20 is passed upwardly toward the heating unit 16, and is guided through a suitable eyelet 22 and a disc tension 24 which isolates the supply package from the remainder of the apparatus. By such isolation variations in tension occasioned by the unwinding of strand S from package 20 are controlled as the strand advances through the tension discs. A lower, positively driven feed roll 26 is provided at the lower end of the heater to cooperate with the upper feed roll device 12 for controlling strand tension in the zone between the upper feed roll device 12 and the lower feed device 26, i.e., the heating and twisting zone, as the yarn is twisted while heated and subsequently cooled.

in operation with the apparatus described to this point, strand S is drawn off package 20, advanced through eyelet 22, disc tension 24, lower feed roll 26 and groove 18 of heating unit 16 to be thereupon engaged by friction twister l and then upper feed roll device 12. Twist is inserted in the strand below friction twister and runs back in the area within groove 16. The strand is thus twisted while heated and subsequently cooled after emergence from groove 16. The upper feed roll device 12 and lower feed roll device 26 are correlated in speed to impart the desired tension in the strand as it is twisted and heated. In the usual fashion, the strand is untwisted as it leaves the exit end of twister It and is directed to upper feed roll device 12 and ultimately to take-up unit 14 in this condition.

It is to be understood that only so much of a false twist texturizing machine and its operation has been described herein as is necessary to a complete understanding of the relationship between such structure and the friction twister of the present invention, and no attempt has been made to define further particulars of the texturizing machine and its operation, reference being directed at this point to the particulars of the specific texturizing apparatus with which the invention might be employed.

With reference now particularly to FIGS. 2 and 3, the friction twister 10 of the present invention is mounted on a swing 30 carried on the frame F of the texturizing machine. The swing is rotatable to move the whorl or cap 32 of a hollow spindle 34 into and out of engagement with an elongated driving belt 36 which extends the full length of the machine and which is common to all of the spindles on the machine. Thus, swing 34) serves as a suitable locator to situate the spindle 34 in an operable, rotating condition against belt 36 or, on the other hand, to displace the spindle from contact with the belt and render the spindle inoperative, i.e., non-rotational as, for example, when the twister is to be threaded up. Swing 3%, by virtue of its mount on the texturizing machine, is adapted to permit spindle 34 to be positioned for driving by either the front or rear side of the belt 36. in this way the spindle can be driven in either a left or right sense to thereby produce strands having S or Z twist.

It has already been stated that twister 10 includes a hollow spindle 3d and a cap 32. The cap 32 is pressfitted or otherwise tightly secured to the upper end of the spindle and a similar cap 38 is likewise pressed or otherwise tightly fitted to the lower end of the spindle. Consequently, caps 32 and 38 together with spindle 34 all rotate as an integral unit. The stationary holder for spindle 34 is constituted as a tubular mount 40 and it is this mount which is clamped in the split section 42 of swing 30 by means of a binding screw 44 (FIG. 3). Ball bearings 46 are provided proximate to opposite ends of the mount 40 for rotatably supporting spindle 34 on the mount and suitable seals 48 are provided adjacent the bearings to retain the lubrication in the bearings as well as to protect them from dust and other foreign matter.

An elastomeric O-ring or friction member 50 is pressed into a recess formed in cap 32 at the upper end of spindle 34 for firm seating therein. A similar tl-ring or friction member 52 is likewise pressed into a further groove in cap 38 at the opposite end of spindle 34. Friction members 50, 52 are firmly seated within their respective caps 32, 33 to a depth so that the mid-line of each is recessed below the end wall of its associated cap. By such seating the friction members are prevented from being dislodged during rotation of the spindle and strand twisting. It is also important to note that each of the friction members 50, 52 has a convex outer face which protrudes outwardly from the end wall of its associated cap by a substantial distance. Further, the internal diameter of each friction member 50, 52 is slightly smaller than the axial bore 54 of spindie 34. Accordingly, when strand S is released for movement to its active position engaged with friction members 50, 52 such engagement is made in a line contact with the friction members to insure the suitable surface contact occurs between the friction members and the strand. 1

With continuing attention to FIGS. 2 and 3 it will be seen that an upright bar 60 is fastened to the outer end of spindle swing 3% by means of a stud 62 (F IG. 3). Bar 60 is positioned parallel to the axis of spindle 34 and is spaced a sufficientdistance from caps 32 and 38 so that rotation of these caps is not interfered with. Moreover, it will be noted that bar 60 is longer than spindle 34 so as to extend both above and below the termini of the spindle. Accordingly, bar 60 provides a support at its opposite ends for upper and lower strand guides 64, 66. Set screws 68 (only one being shown) are suitably threaded into bar 60 to secure the guides 64, 66 in position with the strand-receiving bight or eyelet 70 of each guide aligned coaxially with bore 54 through spindle 34. The eyelets 70 of the guides 64, 66 are not fully closed but, rather, include an opening or slot 72 which is seen in guide 64 in FIG. 3. These slots in guides 64, 66 are substantially wider than the diameter of the strand and, consequently, afford an avenue for release of the strand from the eyelets when it is desired to release the strand for engagement with friction members 50, 52.

Bar 60 also acts as the support for a reversing guide constituted as a pair of spaced apart, semi-circular elements 78, 80 which are secured to the bar by screws 82 passing through the web portions of said elements. Each element 78, 80 has a strand-receiving, ceramic coated peripheral groove 84 disposed in radial alignment with bore 54 as best seen in FIG. 3. The grooves 84 in elements 78, 80 are also vertically aligned with each other to permit the strand S to run therebetween in a generally straight path.

The operation of friction twister will be described next. While it will be appreciated that friction twister 10 could be utilized to twist several strands simultaneously, it will suffice to describe the threading-up procedure for but one strand herein, the procedure being the same for the other strands if plural strands are to be simultaneously twisted by the twister. To this end and during the course of threading up the apparatus described herein the strand S is directed in a substantially straight line through heater groove 18, through eyelet 70 of guide 66 and into the lower, entry end of bore 54 of spindle 32. The path of strand S to groove 18 has been related earlier and need not be repeated. The strand passes upwardly through bore 54 and through eyelet 70 in guide 64. Thus, the strand within bore 54 initially assumes a straight course essentially coaxial with spindle 34 as illustrated by the solid line 90 in FIG. 2. From guide 64 the strand reverses its course and passes downwardly through the grooves 84 in elements 78 and 80 whereupon it is once again threaded through eyelet 70 in guide 66. The strand path from eyelet 70 in guide 64 to the like eyelet in guide 66 is shown by the solid line 92 in FIG. 2. From its second pass through eyelet 70 in guide 66 the strand extends upwardly through bore 54 and through eyelet 70 in guide 64 again and upward to feed roll device 12 and to take-up unit 14 as already described. This path is illustrated by the solid line 94 in FIG. 2.

With the apparatus preliminarily threaded up as just described it will be appreciated that strand S is in an inactive path free of friction members 50, 52 can be manually pulled upward to engage it on feed roll unit 12 and to wrap as few starter winds of the strand on the take-up unit 14, a usual procedure in threading-up the machine, without the restriction to strand advance that would arise if the strand was engaged with friction members. With strand S residing on guides 64, 66 the strand flows freely under only slight resistance to manual pulling and under a force well below the breaking point of the strand.

At this juncture let it be assumed that the apparatus of FIG. 1 is to be started to false twist the strand. The take-up unit 14 is first energized to commence linear advance of the strand thereto from supply package 20. Spindle swing 30 is then rotated to engage cap 32 with belt 36 to rotate the friction twister. The operator then shifts the strand out of eyelets of guides 64, 66, the tension in the strand acting to draw the strand quickly against friction members 50, 52. Consequently, at this point the strand assumes an active position where twist is inserted into the strand. In this active position the strand shifts from the afore-described inactive path to firstly assume a new somewhat angulated position with respect to the axis of bore 54 as shown by the broken line 96 in FIG. 2 where the strand extends from the eyelet 70 of guide 66 to engagement with friction member 50. It is significant to note that in this position the strand does not contact member 52 nor the wall of spindle 34. The strand is next drawn angularly over friction member 50 and into groove 84 of reversing element 78. This strand path is illustrated in FIG. 2 at 98. To insure proper frictional engagement of strand S with friction member 50, the strand is deflected downwardly to groove 84 of the element 78 at an angle of about 5 from the horizontal. Strand S then advances downward through groove 84 of element and exits therefrom to engage friction member 52, the path of the strand here being referenced at 100 in FIG. 2. Strand S moves in path 100 at an angle of about 10 off the horizontal, again to insure good frictional engagement of the strand with friction member 52. The strand then wraps about friction member 52 and is directed upwardly in path 102 (FIG. 2) passing axially through bore 54, devoid of contact with the strand in path 96 and being guided out of the bare via eyelet 70 of guide 64. In FIG. 2 the active path of strand S as shown in broken lines, and the inactive path as shown in solid lines, are seen to be coincident where the strand initially enters the eyelet of guide 66, where the strand exits from the eyelet of guide 64 upwardly to feed roll unit 12, and in the path between elements 78 and 80. This, of course, signifies that the strand path in these zones is not substantially changed irrespective of whether the strand is in its active or inactive position.

At this point in the procedure the strand is advancing while being twisted. Thereupon lower feed roll unit 26 is activated followed by the starting up of the upper feed roll unit 12 to complete the steps leading to operation of the apparatus of FIG. 1 to false twist strand S.

Since certain changes may be made in the above method and apparatus therefor without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative only and not in a limiting sense.

What is claimed is:

1. A method of processing a strand capable of receiving twist comprising the steps of: arranging said strand in a looped path within a zone, said zone provided with a twisting device having a spindle and having friction means thereon for engaging and twisting the strand, disposing the strand within said zone in an inactive position where the strand is proximate to the spindle and disengaged from the friction means thereon, advancing the strand while rotating said spindle, and finally moving said strand to an active position engaged with the friction means to thereby twist the strand.

2. A method of processing a strand capable of receiv ing twist comprising the steps of: arranging said strand in a zone provided with a twisting device having a spindle and having friction means thereon for engaging and twisting the strand, directing said strand in a path defining a loop within said zone, positioning said strand within said zone in an inactive position where the strand is proximate to the spindle and disengaged from the friction means thereon, advancing the strand while rotating said spindle, and finally moving said strand to an active position while maintaining said loop so that said strand is engaged with the friction means to thereby twist the strand.

3. A method of processing a strand capable of receiving twist comprising the steps of: arranging said strand in a zone provided with a twisting device having a spindie and having friction means thereon for engaging and twisting the strand, disposing the strand within said zone in an inactive position where the strand is proximate to the spindle and disengaged from the friction means thereon, advancing the strand while rotating said spindle and tensioning the strand to a first value within said zone, and finally moving said strand to an active position engaged with the friction means to thereby twist the strand, and tensioning the strand to a second value greater than said first value while advancing the strand in its active position.

4. Apparatus for processing an advancing strand capable of receiving twist comprising, rotatable twisting means for engaging the advancing strand, means for rotating said twisting means, and stationary guide means for disposing said strand in an inactive position spaced from said twisting means preliminary to twisting the strand, said guide means including a release portion to permit the path of the advancing strand to be altered by a transfer of the strand to an active position for engagement with said twisting means to thereby impart twist .to the strand as the twisting means is rotated.

5. Apparatus as set forth in claim 4 wherein said twisting means includes at least one friction surface for imparting twist to the strand, and said strand when in said inactive position is spaced from said friction surface.

' disposing the strand in an inactive path spaced from said friction surface preliminary to twisting the strand and for disposing the strand through said bore, said guide means including a release portion to permit transfer of the strand to an active position in engagement with said friction surface to thereby impart twist to the strand as the twisting means is rotated.

7. Apparatus as set forth in claim 6 wherein said friction means includes first and second friction members iii fii d i ifs hl fii 3 5??? fifi s fiiiii isifi guides positioned proximate opposite ends of said bore to guide the strand in an initial pass through said bore while maintaining the strand in its inactive position spaced from said first and second friction members.

8. Apparatus as set forth in claim 7 including reversing means positioned in a plane between said first and second guides for redirecting the strand in a loop for a second pass through said bore.

9. Apparatus as set forth in claim 8 wherein the first guide is proximate a strand entry end of said bore and said second guide is proximate a strand exit end of said bore, and the strand when in its active position is guided in its initial pass into the bore by said first guide and advances in a path spaced from said second guide to engage said friction means, and the strand in its second pass when its active position is guided into the bore in a path spaced from said first guide and in engagement with said firction means and is guided out of the exit end of the bore by said second guide.

10. Apparatus as set forth in claim 9 when said friction means includes a first friction ring disposed at the entry end of said bore and a second friction ring disposed at the exit end of said bore. 

1. A method of processing a strand capable of receiving twist comprising the steps of: arranging said strand in a looped path within a zone, said zone provided with a twisting device having a spindle and having friction means thereon for engaging and twisting the strand, disposing the strand within said zone in an inactive position where the strand is proximate to the spindle and disengaged from the friction means thereon, advancing the strand while rotating said spindle, and finally moving said strand to an active position engaged with the friction means to thereby twist the strand.
 2. A method of processing a strand capable of receiving twist comprising the steps of: arranging said strand in a zone provided with a twisting device having a spindle and having friction means thereon for engaging and twisting the strand, directing said strand in a path defining a loop within said zone, positioning said strand within said zone in an inactive position where the strand is proximate to the spindle and disengaged from the friction means thereon, advancing the strand while rotating said spindle, and finally moving said strand to an active position while maintaining said loop so that said strand is engaged with the friction means to thereby twist the strand.
 3. A method of processing a strand capable of receiving twist comprising the steps of: arranging said strand in a zone provided with a twisting device having a spindle and having friction means thereon for engaging and twisting the strand, disposing the strand within said zone in an inactive position where the strand is proximate to the spindle and disengaged from the friction means thereon, advancing the strand while rotating said spindle and tensioning the strand to a first value within said zone, and finally moving said strand to an active position engaged with the friction means to thereby twist the strand, and tensioning the strand to a second value greater than said first value while advancing the strand in its active position.
 4. Apparatus for processing an advancing strand capable of receiving twist comprising, rotatable twisting means for engaging the advancing strand, means for rotating said twisting means, and stationary guide means for disposing said strand in an inactive position spaced from said twisting means preliminary to twisting the strand, said guide means including a release portion to permit the path of the advancing strand to be altered by a transfer of the strand to an active position for engagement with said twisting means to thereby impart twist to the strand as the twisting means is rotated.
 5. Apparatus as set forth in claim 4 wherein said twisting means includes at least one friction surface for imparting twist to the strand, and said strand when iN said inactive position is spaced from said friction surface.
 6. Apparatus for processing and advancing strand capable of receiving twist comprising, rotatable twisting means including a rotatable spindle having a bore therethrough and including a friction means, said friction means including at least one friction surface for engaging and imparting twist to the strand, means for rotating said twisting means, and guide means for disposing the strand in an inactive path spaced from said friction surface preliminary to twisting the strand and for disposing the strand through said bore, said guide means including a release portion to permit transfer of the strand to an active position in engagement with said friction surface to thereby impart twist to the strand as the twisting means is rotated.
 7. Apparatus as set forth in claim 6 wherein said friction means includes first and second friction members arranged on said spindle at spaced apart positions, and said guide means includes first and second strand guides positioned proximate opposite ends of said bore to guide the strand in an initial pass through said bore while maintaining the strand in its inactive position spaced from said first and second friction members.
 8. Apparatus as set forth in claim 7 including reversing means positioned in a plane between said first and second guides for redirecting the strand in a loop for a second pass through said bore.
 9. Apparatus as set forth in claim 8 wherein the first guide is proximate a strand entry end of said bore and said second guide is proximate a strand exit end of said bore, and the strand when in its active position is guided in its initial pass into the bore by said first guide and advances in a path spaced from said second guide to engage said friction means, and the strand in its second pass when its active position is guided into the bore in a path spaced from said first guide and in engagement with said firction means and is guided out of the exit end of the bore by said second guide.
 10. Apparatus as set forth in claim 9 when said friction means includes a first friction ring disposed at the entry end of said bore and a second friction ring disposed at the exit end of said bore. 